1. Field of the Invention
The present invention relates to charging and discharging of a battery and, more particularly, to a battery charging and discharging apparatus and a battery charging and discharging method which effectively reduce heat loss arising during charging and discharging of the battery and achieve recycling of the direct-current (DC) power.
2. Description of the Prior Art
In recent years, as the technology evolves constantly, there are often a wide variety of computer equipments available in the market. Among these computer equipments, notebooks not only gradually become the mainstream in the market, but also become one of the indispensable tools for people in the modern life due to a small size, easy to carry, small occupied space, etc.
In general, it usually requires a number of cells in series to provide the required voltage for notebooks in the battery-powered mode. In the battery manufacturing process, the testing in the charging and discharging of the battery must be carried on to ensure that the battery capacity meets the required specifications.
However, when the traditional charging and discharging measuring equipment examines the charging and discharging of the battery, it tends to cause large amount of heat loss, and the energy usage is not ideal enough. Please refer to FIG. 1 which illustrates a schematic diagram of the charging and discharging circuit of the traditional charging and discharging measuring equipment for charging of a battery B.
As shown in FIG. 1, the charging and discharging circuit includes a constant voltage/constant current controlling transistor Q, a current-limiting resistor R4, a constant voltage controlling integrated circuit U1, a constant current controlling integrated circuit U2, a current readback amplifier U3, and a voltage readback amplifier U4. Vs is the maximum charging voltage for the battery B; Is is the maximum charging current for the battery B; Vcc is the primary power supply for charging. Because the charging and discharging circuit of the traditional charging and discharging measuring equipment is of a voltage-fixed type, the constant voltage/constant current controlling transistor Q has considerable heat loss in the beginning of the constant current charging for the battery B by the charging and discharging circuit.
In addition, during discharging of the battery B activated by the traditional charging and discharging measuring equipment, because an electronic load circuit is introduced mostly to consume the discharging energy from the battery B directly, the charging and discharging measuring equipment will have large amount of heat loss, causing the poor energy usage and even failure to meet the increasingly stringent safety regulations.
In order to achieve the testing conditions for charging and discharging of the battery prescribed by the safety regulations, although being able to recycle the discharging energy, some charging and discharging measuring equipments often convert the discharging energy into an alternating current and then feedbacks it to the DC power system. In this way, because the feedbacked alternating current causes the original power quality factor to reduce easily, the kindness of recycling of the discharging energy is greatly reduced instead.
Accordingly, the main scope of the invention is to provide a battery charging and discharging apparatus and a battery charging and discharging method to solve the aforementioned problems.